Generally, a vehicle seat is configured of a seat cushion and a seat back to maintain an on-board posture of a passenger and is classified into a separator type seat which is formed at a driver's seat and a passenger's seat to enable only one person to be seated and a bench type seat which is formed at a back of the driver's seat and the passenger's seat to enable several persons to be simultaneously seated.
The separator type seat which is formed at the driver's seat and the passenger's seat may control a vehicle seat to meet a driver's body type and a passenger's body type so as to enable the driver to maintain a posture suitable for driving, in which a seat back serving as a back to enable the passenger to have a rest is provided with a reclining apparatus controlling an angle back and forth.
The separator type seat separately manufactured from a seat is configured to freely control an angle of a back by operating a recliner formed therebetween to allow a driver or a passenger to be stably and conveniently seated in the state in which he/she appropriately may control the position and back of the seat according to his own body type.
FIG. 1 is plan view of a recliner 10 for a general vehicle and FIG. 2 is a partially enlarged view of the recliner 10. As illustrated, the recliner 10 is configured of an upper gear 1 having an internal tooth formed on an inner peripheral surface thereof and connected to a seat back to control an inclination angle of the seat back by rotation, a lock gear 2 provided with an external tooth engaged with the internal tooth and locking or unlocking a rotation of the upper gear 1 by a linear reciprocating motion, a holder 3 provided with a guide surface 3a to guide the linear reciprocating motion of the lock gear 2, a cam 4 controlling the linear reciprocating motion of the lock gear 2 by rotation, and an elastic member 5 applying an elastic force to the cam 4.
The recliner 10 having the above configuration is configured so that the lock gear 2 is linearly reciprocated according to a restriction condition of the cam 4 to control the inclination of the seat back to a passenger desired position and the external tooth is engaged with the internal tooth formed at the upper gear 1 to fix the upper gear 1 at a desired position. In this case, since the lock gear 2 moves along the guide surface 3a, a gap G (see FIG. 2) is required between the lock gear 2 and the guide surface 3a and when the gap G is increased according to an accumulation of machining tolerance of the lock gear 2 and the holder 3, the motion of the holder 3 is large in the state in which the lock gear 2 is engaged with the upper gear 1 and thus clearance is generated and the seat back vibrates and thus passenger's comfort is degraded.
However, the gap G may not be removed due to the accumulation of the machining tolerance of parts of the lock gear 2 and the holder 3. In particular, to smooth the linear reciprocating motion of the lock gear 2, the gap G needs to be formed. Therefore, the clearance factor of the recliner 10 due to the gap G always exists.
Therefore, a technology to ensure the strength of the recliner by preventing the seat back from vibrating by offsetting the clearance generated by the gap G and keeping the stable engagement of the upper gear 1 with the lock gear 2 depending on a front or back external force load direction of the seat back is required.